Engine with improved injector tube sealing



L. FALKOWSKY TH IMPROVED INJECTOR TUBE SEALING Aug 8, 1967 ENGINE W1 Filed June INVENTOR. fi/em? L: fid/kawzf z BY Arrow/WW United States Patent 3,334,617 ENGINE WITH IMPROVED INJECTOR TUBE SEALING Glenn L. Pallrowsky, Garden City, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed June 16, 1965, Ser. No. 464,480 4 Claims. (Cl. 123-32) ABSTRACT OF THE DISCLOSURE An internal combustion engine cylinder assembly includes an injector-receiving copper tube extending through the coolant water jacket wherein leakage between the coolant jacket and combustion chamber due to thermal distortion of the combustion chamber wall is prevented by providing an annular ring on the tube, which engages an annular sealing surface in the lower wall extending parallel to the plane of the wall. The sealing force on the ring is obtained by clamping the injector against an annular surface of the tube interior adjacent the position of the annular ring. The tube end is deformed into a counterbore on the cylinder head surface to retain it in the cylinder head and resilient sealing means are provided to prevent leakage through the upper wall opening of the cylinder head.

This invention relates to internal combustion engines and, more particularly, to engines having improved injector tube sealing means to prevent leakage of combustion gases into the cooling water jacket and vice versa.

It is known in diesel engine construction, where an injector is provided to supply fuel to the engine combustion chamber, to cool the injector as well as the combustion chamber wall by means of liquid coolant circulated through a cooling jacket. In order to separate the injector body from direct contact by the cooling liquid as well as to prevent leakage of the cooling liquid into the combustion chamber when an injector is removed temporarily, it is common practice to provide an injector tube or cooling sleeve surrounding the injector, extending through the cooling water jacket and providing a positive seal with the walls of the cooling water jacket.

Such a construction is shown in FIGURE 6 of the patent to Reddy et al. 2,686,503 where the injector tube 49 is shown extending through the water jacket of the cylinder head 43 and surrounding the body of injector 51. A resilient seal is provided between a flared portion at the upper edge of the injector tube and a counterbored portion of the upper cylinder head wall to prevent leakage of coolant therethrough. Adjacent the lower end of the tube, a tapered portion thereof is seated against the lower cylinder head wall by the clamping force of the injector exerted on a cooperating tapered portion of the injector body. This sealing force prevents leakage of combustion gases from the combustion chamber into the cooling water jacket as well as into the interior of the injector tube.

In order to retain the tube in place when the injector is removed,'the cylindrical appearing lower end of the tube is flared or otherwise deformed into a reverse taper opening provided on the combustion chamber side of the lower wall. The strength of this joint is not generally adequate to prevent leakage of combustion pressures during engine operation.

The injector cooling tube is commonly made of a high heat conducting material such as copper in order to provide adequate cooling for the fuel injector. This has the additional advantage that the copper body is easily deformed to provide for retention in the cylinder head lower 3,334,617 Patented Aug. 8, 1967 wall as well as permitting some conforming to the injector and cylinder head wall sealing surfaces.

With prior art constructions similar to that described above, the higher combustion pressures reached in high output engines have caused leakage problems to occur in engine operation. A cause of these problems is believed to be the deformation of the lower cylinder head wall in the plane of the wall caused by stresses due to the high temperatures and pressures reached in a combustion chamber. These stresses eventually result in permanent deformation of the injector cooling tube and the cylinder head wall in the plane of the wall itself so that, when the engine is shut down, cooling of the wall causes it to pull away from the injector cooling tube, thereby permitting leakage of the cooling water into the engine combustion chamber.

The present invention has supplied a solution to the problem of leakage caused by such deformation of the cylinder head wall. This is accomplished by changing the orientation of the sealing surfaces of the injector tube and lower cylinder head wall so that these surfaces lie in a plane parallel to that of the lower wall. This permits some planar deformation of the wall without causing separation of the sealing surfaces and, therefore, without destroying the seal.

These and other advantages of the present invention will be more readily understood from the following description and drawings in which:

FIGURE 1 is a fragmentary cross-sectional view of an engine embodying the invention;

FIGURE 2 is a fragmentary cross-sectional view of the engine of FIGURE 1 showing the injector cooling tube secured in the lower cylinder head wall and with the injector removed; and

FIGURE 3 is a fragmentary cross-sectional view of the injector tube of FIGURE 2 before installation in the engine cylinder head.

Referring now to the drawings, FIGURE 1 shows an internal combustion engine 10 of the compression ignition type and having the usual cylinder block 12 carrying a cylinder liner 14 in which a piston 16 is reciprocably disposed. A cylinder head 18 is secured along the upper face of the block 12 and includes upper and lower walls 20 and 22, respectively, which partially define a cooling water jacket 24. The lower wall 22 of the cylinder head cooperates with the crown of piston 16 to define a combustion chamber 26.

A pair of openings 30 and 32 are provided through the upper and lower cylinder head walls, respectively, the two openings being coaxially disposed and receiving an injector tube or sleeve 34 which may be made of copper or other suitable material. The injector tube includes a cylindrical upper portion having an outwardly directed flange 36 at the upper end, which engages an O-ring seal 38 carried in a counterbored portion 40 of opening 30 to prevent leakage of coolant from the water jacket 24.

As best seen in FIGURE 2, the lower end 42 of tube 34, which is received in opening 32, is generally tapered and includes an annular ring member 44. Member 44 may be made from the same material as the rest of the injector tube and is secured, as by soldering, to the tapered portion 42. This ring could equally well be formed integral with the injector tube; however, the two-piece construction shown here was adopted for ease of manufacture. Ring 44 includes an annular surface 46 which seats against a cooperating annular abutment 48, provided in a counterbored portion 50 of opening 34. A predetermined clearance 52 is provided between the outer diameter of' tube 34 is a generally cylindrical portion 54, the end of which is deformed to create a flanged portion 56. This portion fills in a counterbore 58 extending upwardly from the combustion chamber surface 60 of wall 22 and positively retains tube 34 in wall 22 and in the cylinder head.

FIGURE 3 shows the lower end of tube 34 before installation in the cylinder head. The tapered portion 42 with the attached ring 44 are as shown in FIGURE 2, but the cylindrical portion 54 is shown in its undeformed state. The interior of the tube includes machined out portions 62 and 64 which leave a tapered annular seat 66 on the interior, adjacent the location of ring 44. At the very end, within cylindrical portion 54, is a cylindrical opening 68. Upon installation of the tube in the cylinder head, as shown in FIGURE 2, seat 66 and opening 68 are machined to their final form and size, the latter being changed to a tapered configuration.

Injector tube 34 provides for the mounting of an injector 70 in the cylinder head and extending therethrough to supply fuel to combustion chamber 26. The injector includes a tip portion 72, which extends with slight clearance through opening 68, and a tapered end portion 74 which bears against seat portion 66 of the injector tube, forming a sealed joint. The injector is positively clamped against seat 66 by clamp means 76 which are threadably secured to the cylinder head. The clamping force creates a positive seal between tapered end 74 and annular seat 66 and forces the injector tube downwardly, exerting pressure on the abutting surfaces 46 and 48 of the tube 34 and wall 22, which positively seals that joint.

In operation, expansion and contraction of wall 24 in its plane of action has no effect upon the force which seats surface 46 of the injector tube against abutment 48 of the wall, since the distortion is in a plane parallel thereto. Clearance 52 permits some movement to occur without binding or causing any deformation of the local sealing surfaces. Thus, a positive seal is maintained against the leakage of combustion gases from the combustion chamber 26 into the water jacket 24 and also from the combustion chamber 26 to the interior of tube 34. At the same time, the flange 56 retains injector tube 34 in wall 22 with a sufliciently strong force to prevent leakage of the cooling liquid from jacket 24 into combustion chamber 26 at such times as the engine is shut down and injector 70 is temporarily removed therefrom, such as for servicing.

The above described embodiment of the present invention discloses the best mode presently known for using my invention. However, it is obvious that modifications or changes may be made within the spirit and scope of the invention disclosed herein. The invention is, accordingly, not to be limited except by the language of the following claims.

I claim:

1. In an internal combustion engine having a combustion chamber,

a cylinder head having upper and lower walls partially defining a cooling liquid jacket, said lower wall closing one side of said combustion chamber, pair of axially aligned openings through said upper and lower walls, said lower wall including an annular abutment bounding said lower wall opening and lying in a plane generally parallel to the plane of said lower wall and a counterbored portion at the combustion chamber end of said opening and facing said combustion chamber, an injector tube carried in said wall openings and extending through said cooling liquid jacket, said injector tube including an annular surface in engagement with said annular abutment, a flanged portion of said injector tube extending into said counterbored portion and retaining said injector tube in position in said cylinder head, said injector tube further including an annular seat disposed around the interior of said injector tube adjacent the position of said annular surface and fuel injector clampingly secured in said cylinder head and extending through said injector tube, said fuel injector including an end portion engaging said injector tube annular seat, whereby at least a portion of said injector clamping force acts to seat said injector on the annular seat of the injector tube and increases the seating force of the injector tube annular surface on the annular abutment of said lower cylinder head wall to prevent the leakage of combustion gases into said cooling liquid jacket as well as into the interior of said injector tube, said increased seating force being unaffected by relative movement of said annular surface and said annular abutment occurring in the plane of said lower wall. In an internal combustion engine having a combuschamber,

cylinder head having upper and lower walls partially defining a cooling liquid jacket, said lower wall closing one side of said combustion chamber,

pair of axially aligned openings through said upper and lower walls, said lower wall including an annular abutment bounding said lower wall opening and lying in a plane generally parallel to the plane of said lower wall,

an injector tube carried in said wall openings and ex- 3. tion tending through said cooling liquid jacket, said injector tube having a tapered portion adjacent one end thereof and an annular ring around the exterior of said tapered portion, said ring having an annular surface in engagement with said annular abutment, said injector tube further including a tapered annular seat disposed around the interior of said tapered portion adjacent the position of said annular ring, fuel injector clampingly secured in said cylinder head and extending through said injector tube, said fuel injector including a tapered end engaging said injector tube tapered annular seat, whereby at least a portion of said injector clamping force acts to seat said injector on the tapered annular seat of the injector tube and creates a seating force of the annular ring on the annular abutment of said lower cylinder head wall to prevent the leakage of combustion gases into said cooling liquid jacket as well as into the interior of said injector tube, said seating force being unaffected by relative movement of said annular surface and said annular abutment occurring in the plane of said lower wall.

In an internal combustion engine having a combuschamber,

cylinder head having upper and lower walls partially defining a cooling liquid jacket, said lower wall closing one side of said combustion chamber,

pair of axially aligned openings through said upper and lower walls, said lower wall including an annular abutment bounding said lower wall opening and lying in a plane generally parallel to the plane of said lower wall and said lower wall opening having an enlarged portion at the combustion chamber side of said wall,

an injector tube carried in said wall openings and extending through said cooling liquid jacket, said injector tube having a tapered portion adjacent one end thereof and an annular ring around the exterior of said tapered portion, said ring having an annular surface in engagement with said annular abutment, a deformed portion of said injector tube extending into the enlarged portion of said lower wall opening to retain said injector tube in position in said cylinder head and fuel injector clampingly secured in said cylinder head and extending through said injector tube, said fuel injector including an end portion engaging said injector tube, whereby at least a portion of said injector clamping force creates a seating force of the injector tube annular surface on the annular abutment of said lower cylinder head wall to prevent the leakage of combustion gases into said cooling liquid jacket as well as into the interior of said injector tube, said seating force being unaffected by relative movement of said annular surface and said annular abutment occurring in the plane of said lower wall.

4. In an internal combustion engine having a combustion chamber,

a cylinder head having upper and lower walls partially defining a cooling liquid jacket, said lower wall closing one side of said combustion chamber,

a pair of axially aligned openings through said upper and lower walls, said lower -wall including a first counterbored portion facing toward said cooling liquid jacket and bounding said lower wall opening and including an annular abutment lying in a plane generally parallel to the plane of said lower wall and a second counterbored portion at the combustion chamber end of said opening and facing said combustion chamber,

an injector tube carried in said wall openings and ex tending through said cooling liquid jacket, said injector tube having a flared portion at one end thereof and a tapered portion adjacent the other end thereof, an annular ring around the exterior of said tapered portion and having an annular surface in engagement with said lower wall annular abutment and other portions separated from said lower wall by a positive clearance, a flanged portion of said injector tube extending into said second counterbored portion and retaining said injector tube in position in said cylinder head, said injector tube further including a tapered annular seat disposed around the interior of said tapered portion adjacent the position of said annular ring,

resilient seal means between said injector tube flared portion and said upper wall to prevent loss of coolant from said cooling liquid jacket, and

a fuel injector clampingly secured in said cylinder head and extending through said injector tube, said fuel injector including a tapered end engaging said injector tube tapered annular seat whereby at least a portion of said injector clamping force acts to seat said injector on the tapered annular seat of the injector tube and increases the seating force of the annular ring on the annular abutment of said lower cylinder head wall to prevent the leakage of combustion gas into said cooling liquid jacket as well as into the interior of said injector tube.

References Cited UNITED STATES PATENTS 2,858,813 11/1958 Haas 12332 FOREIGN PATENTS 1,053,609 9/ 1953 France.

510,439 8/1939 Great Britain. 512,114 8/1939 Great Britain.

LAURENCE M. GOODRIDGE, Primary Examiner. 

1. IN AN INTERNAL COMBUSTION ENGINE HAVING A COMBUSTION CHAMBER, A CYLINDER HEAD HAVING UPPER AND LOWER WALLS PARTIALLY DEFINING A COOLING LIQUID JACKET, SAID LOWER WALL CLOSING ONE SAID OF COMBUSTION CHAMBER, A PAIR OF AXIALLY ALIGNED OPENINGS THROUGH SAID UPPER AND LOWER WALLS, SAID LOWER WALL INCLUDING AN ANNULAR ABUTMENT BOUNDING SAID LOWER WALL OPENING AND LYING IN A PLANE GENERALLY PARALLEL TO THE PLANE OF SAID LOWER WALL AND A COUNTERBORED PORTION AT THE COMBUSTION CHAMBER END OF SAID OPENING AND FACING SAID COMBUSTION CHAMBER, AN INJECTOR TUBE CARRIED IN SAID WALL OPENINGS AND EXTENDING THROUGH SAID COOLING LIQUID JACKET, SAID INJECTOR TUBE INCLUDING AN ANNULAR SURFACE IN ENGAGEMENT WITH SAID ANNULAR ABUTMENT, A FLANGED PORTION OF SAID INJECTOR TUBE EXTENDING INTO SAID COUNTERBORED PORTION AND RETAINING SAID INJECTOR TUBE IN POSITION IN SAID CYLINDER HEAD, SAID INJECTOR TUBE FURTHER INCLUDING AN ANNULAR SEAT DISPOSSED AROUND THE INTERIOR OF SAID INJECTOR TUBE ADJACENT THE POSITION OF SAID ANNULAR SURFACE AND A FUEL INJECTOR CLAMPINGLY SECURED IN SAID CYLINDER HEAD AND EXTENDING THROUGH SAID INJECTOR TUBE, SAID FUEL INJECTOR INCLUDING AN END PORTION ENGAGING SAID INJECTOR TUBE ANNULAR SEAT, WHEREBY AT LEAST A PORTION OF SAID INJECTOR CLAMPING FORCE ACTS TO SEAT SAID INJECTOR ON THE ANNULAR SEAT OF THE INJECTOR TUBE AND INCREASES THE SEATING FORCE OF THE INJECTOR TUBE ANNULAR SURFACE ON THE ANNULAR ABUTMENT OF SAID LOWER CYLINDER HEAD WALL TO PREVENT THE LEAKAGE OF COMBUSTION GASES INTO SAID COOLING LIQUID JACKET AS WELL AS INTO THE INTERIOR OF SAID INJECTOR TUBE, SAID INCREASED SEATING FORCE BEING UNAFFECTED BY RELATIVE MOVEMENT OF SAID ANNULAR SURFACE AND SAID ANNULAR ABUTMENT OCCURRING IN THE PLANE OF SAID LOWER WALL. 